TITLE:
Effect of Chromium on Magnetic Characteristics of Powder Processed Fe-0.35wt%P Alloy
AUTHORS:
Deepika Sharma, Kamlesh Chandra, Prabhu Shankar Misra
KEYWORDS:
Glassy Ceramic Coating; Preform Forging; Coercivity
JOURNAL NAME:
Journal of Minerals and Materials Characterization and Engineering,
Vol.10 No.7,
June
6,
2011
ABSTRACT: The present investigation deals with hot powder preform forging technique for the development
of high density iron-phosphorus based alloys. These alloys are known for hot-shortness and are
therefore not considered suitable for high temperature working. To remove this problem proper
soaking at high temperature to eliminate iron- phosphide eutectic and bring entire phosphorus
into solution in iron was aimed. Attempting hot forging thereafter completely eliminates hot as
well as cold shortness and thereby helps to form these alloys into very thin sheets. It has also
been possible to eliminate the use of costly hydrogen atmosphere during sintering by use of
addition of carbon as a reducing agent to form CO gas within the compact by reacting with
oxygen of iron powder particles. The glassy ceramic coating applied over the compact serves as
a protective coating to avoid atmospheric oxygen attack over the compact held at high
temperature. Combined application of carbon and glassy ceramic coating has lead to economy
in P/M processing for soft magnetic applications. Fe- 0.07C- 0.3O- 0.35wt% P- 0.35wt% Cr
alloy so formed yielded coercivity as low as 0.42 Oe, resistivity as high as 21.8 μcm and total
loss as low as 0.170 W/Kg. Such a combination of properties may suit their application in
magnetic relays and transformer cores.